<!DOCTYPE HTML>
<title>OpenLayers Simplest Example</title>
<div id="demoMap" style="height:800px"></div>
<script src="js/OpenLayers.js"></script>
<script>
    map = new OpenLayers.Map("demoMap");
    map.addLayer(new OpenLayers.Layer.OSM());
    map.zoomToMaxExtent();
</script>